Various approaches to increasing the performance and output of an internal combustion engine (ICE) have been developed. One such approach includes injecting nitrous oxide (NOS) into the intake system of an engine to increase engine output. NOS injection may be performed in a variety of contexts, such as industrial and racing settings, for example.
In a typical implementation for performing NOS injection in an ICE, a pressurized reservoir is used to store NOS, whose pressure inside the reservoir is monitored by a pressure gauge. A high pressure line connects the reservoir to an electronic solenoid, which may be operated by a switch that is actuated according to intake throttle position, or via manual control applied by a vehicle operator. Another high pressure line connects the solenoid to an injector that is mounted in the engine intake system and which may have a high tolerance orifice for injecting NOS. The size of the orifice may at least partially determine the additional engine output afforded by NOS injection. To avoid undesired (e.g., lean) operation, additional amounts of a fuel (e.g., gasoline, diesel) with which the engine is designed to operate may be injected in approximate proportion to the amount of NOS injected. The injection of additional nominal fuel may be carried out in various suitable manners, using a so-called “wet” or “dry” injection system. In a wet injection system, a secondary fuel system introduces added fuel that accompanies NOS, whereas in a dry injection system, an existing fuel system (e.g., factory-installed) is utilized to add fuel.
The results of NOS injection may vary greatly with a variety of engine operating and environmental variables. Consequently, performing NOS injection in certain variable ranges, and/or without consideration of some variables, can result in undesired or degraded engine operation. Further, the difficulty of installing a NOS injection system that provides both desired NOS boosting and engine operation may be exacerbated by its typically aftermarket nature; being an aftermarket part, installation is typically carried out by a vehicle operator or third-party establishment (e.g., auto body shop), both of which are typically relegated to adapting an existing engine control unit (ECU) to the NOS injection system. Lacking the ability to design an ECU for compatibility with NOS boosting, modifications to the existing (e.g., factory-installed) ECU may be performed and/or new components added (e.g., fuel control components, switches), which may introduce potential points of degradation.
As such, there exists a need for an integrated NOS injection system in which a variety of operating and environmental variables can be processed at a common ECU and used to control NOS injection.